Imaging system for obtaining quantative perfusion indices

Abstract

A bolus containing optical and MRI contrast agents is administered to a patient for determining quantitative perfusion indices from perfusion weighted magnetic resonance imaging analysis (PWI). The optical contrast agent time-concentration data, which can be obtained non-invasively, is used to define an arterial input function. The MRI contrast agent time concentration can be non-invasively determined using MRI to define a tissue function. An MRI time-signal curve can be determined by deconvolving the arterial and tissue functions. In one embodiment, SVD is used to determine a residue function from which a flow map can be computed.

What is claimed is:  
     
       1. A method for determining quantitative blood perfusion indices, comprising: 
       administering a bolus containing an optical contrast agent and an MRI (Magnetic Resonance Imaging) contrast agent;  
       determining an arterial input function from optical contrast agent concentration samples after the bolus was administered;  
       determining a tissue function from MRI contrast agent samples in a tissue volume of interest, wherein the contrast optical agent concentration samples and the MRI contrast agent concentration samples are correlated in time;  
       determining at least one quantitative perfusion index from the arterial input function and the tissue function.  
     
     
       2. The method according to  claim 1 , wherein the optical contrast agent includes ICG (Indocyanine Green). 
     
     
       3. The method according to  claim 1 , wherein the MRI contrast agent includes Gd-DTPA (Gadopentetate dimeglumine pentaacetic acid). 
     
     
       4. The method according to  claim 1 , further including deconvolving an MR signal-time curve from the arterial input function and the tissue function to derive the at least one quantitative perfusion index. 
     
     
       5. The method according to  claim 4 , further including using SVD (Singular Value Decomposition) to deconvolve the MR signal time curve. 
     
     
       6. The method according to  claim 4 , further including computing a flow map or a blood volume map. 
     
     
       7. The method according to  claim 6 , further including determining a residue function from the arterial input function and the tissue function and using the residue function to compute the flow map. 
     
     
       8. The method according to  claim 1 , further including using optical densitometry to determine the optical contrast agent concentration. 
     
     
       9. The method according to  claim 1 , further including taking blood samples to determine the optical contrast agent concentration. 
     
     
       10. A method for determining quantitative perfusion indices, comprising: 
       administering a bolus containing an optical contrast agent and an MRI (Magnetic Resonance Imaging) contrast agent;  
       determining an arterial input function C a (t) from the optical contrast agent;  
       determining a tissue function C VOI (t) from the MRI contrast agent;  
       deconvolving an MR signal-time curve from the arterial input function C a (t) and the tissue function C VOI (t) based on              C   VOI          (   t   )       =       F   t            ∫   0   t              C   a          (   τ   )            R        (     t   -   τ     )               τ             ,                   
        where R(t) is a residue function describing the fraction of MRI contrast agent at time t, and F t  represents tissue flow.  
     
     
       11. The method according to  claim 10 , further including using SVD (Singular Value Decomposition) to deconvolve the MR signal-time curve. 
     
     
       12. The method according to  claim 10 , wherein the optical contrast agent includes ICG (Indocyanine Green) and the MRI contrast agent includes GDA (gadopentate dimefluminepentaacetic acid). 
     
     
       13. The method according to  claim 10 , wherein the bolus comprises about 0.125 mg/ml ICG (Indocyanine Green) and about 457 mg mg/ml GDA (gadopentate dimefluminepentaacetic acid). 
     
     
       14. A bolus solution for intravascular injections comprising: 
       an optical contrast agent including Idocyanine Green; and  
       an MRI (Magnetic Resonance Imaging) contrast agent including gadopentate dimegluminepentaacetic acid.  
     
     
       15. The solution according to  claim 14 , wherein the Indocyanine Green has a concentration ranging from about 0.01 to 50% by weight based on the total weight of the composition. 
     
     
       16. The solution according to  claim 14 , wherein the gadopentate dimegluminepentaacetic acid has a concentration ranging from about 0.001M to about 0.5M. 
     
     
       17. The solution according to  claim 14 , wherein the optical contrast agent can provide an arterial input function and the MRI (Magnetic Resonance Imaging) contrast agent can provide a tissue function.